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alex79 · 03-22-2006, 03:03 AM

What is the difference between

Code:

Select * from tablea a join tableb b on a.id=b.id
        where id=100

and

Code:

Select * from tablea a join tableb b on a.id=b.id and a.id=100

Is the second sintax faster? in first case the script will realise the join after all rows from tablea and after the join is complete will filter after the id=100 and is second case the join will be realised only after the row where id=100? (if yes then second case i think is much faster)

any opinions?

03-22-2006, 03:03 AM
alex79 Confirmed User Join Date: Jun 2002 Location: france Posts: 996	SQL question What is the difference between Code: Select * from tablea a join tableb b on a.id=b.id where id=100 and Code: Select * from tablea a join tableb b on a.id=b.id and a.id=100 Is the second sintax faster? in first case the script will realise the join after all rows from tablea and after the join is complete will filter after the id=100 and is second case the join will be realised only after the row where id=100? (if yes then second case i think is much faster) any opinions? __________________